The overall goal of this project is to identify leishmanial antigens that have diagnostic and immunoprophylactic potential and to clone the corresponding antigen genes to enable production of large quantities of the antigens. Antigens with diagnostic potential will be identified initially using immunoprecipitation and immunoblot assays employing sera from humans with current or past infections. The diagnostic utility of these antigens derived from both the parasite or cloned parasite genes will be confirmed using serological (ELISA) assays. Protective antigens will be initially identified using a series of in vitro assays employing T lymphocytes, including human and mouse T cell lines and clones. Confirmatory assays of the ability of these antigens to protect against infection will be tested in animal systems. Recombinant DNA libraries will be prepared from mRNA (cDNA) and genomic DNA using standard techniques. The cloned genes of interest will be identified using immunoscreening and screening with synthetic oligonucleotides. The identity of the isolated cloned genes as the antigens of interest will be confirmed and the cloned genes will be modified if needed to optimize antigen production. The antigen products of the cloned genes will be tested for their utility as diagnostic and immunoprophylactic reagents.